skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The impact of cooling rates on the microstructure of Al-U alloys

Journal Article · · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science
; ;  [1];  [2]
  1. Nuclear Research Center-Negev, Beer-Sheva (Israel)
  2. Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Materials Engineering

The impact of cooling rates on the microstructure of Al-U alloys was studied by optical, scanning electron, and transmission electron microscopy. A variety of solidification techniques were employed to obtain cooling rates ranging between 3 {times} 10{sup {minus}2} and 10{sup 6} K/s. High-purity uranium (99.9 pct) and high-purity aluminum (99.99 pct), or commercially pure type Al-1050 aluminum alloys were used to prepare Al-U alloys with U concentration ranging between 3 and 22 wt pct. The U concentration at which a coupled eutectic growth was observed depends on the cooling rates imposed during solidification and ranged from 13.8 wt pct for the slower cooling rates to more than 22 wt pct for the fastest cooling rates. The eutectic morphology and its distribution depends on the type of aluminum used in preparing the alloys and on the cooling rates during solidification. The eutectic in alloys prepared from pure aluminum was evenly distributed, while for those prepared from Al-1050, the eutectic was unevenly distributed, with eutectic colonies of up to 3 mm in diameter. Two lamellar eutectic structures were observed in alloys prepared from pure aluminum containing more than 18 wt pct U, which solidified by cooling rates of about 10 K/s. One structure consisted of the stable eutectic between UAl{sub 4} and Al lamella. The other structure consisted of a metastable eutectic between UAl{sub 3} and Al lamella. At least three different eutectic morphologies were observed in alloys prepared from Al-1050.

Sponsoring Organization:
USDOE
OSTI ID:
484852
Journal Information:
Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Vol. 28, Issue 4; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English